Amrûnril
Hero
Agreed. SS and GWM are some of the only Feats that people inclined towards character optimization seriously consider over +2 to your primary ability score. That makes them the best-balanced Feats, in my book. Others could use a buff to bring them up to that level.
I'd agree a lot of feats could use buffs, but bringing them all to this level woud have the downside of leaving non-primary ability score increases even further behind.
Ultimately, I think characters relying on single ability scores for so much of their combat effectiveness is the game's biggest balance issue, and both feats and non-primary scores end up as casualties of that.